Mechanisms and prediction of severe cutaneous adverse drug reactions

<p> Both drug and patient characteristic factors can contribute to the adverse drug reactions (ADRs), and when the latter contributes largely, these ADRs are generally difficult to be predicted for their occurrence in the non-clinical stage. In general, appropriate animal models and in vitro systems based on their mechanism are important for evaluation of ADRs in the non-clinical stage.</p><p> Among the idiosyncratic ADRs, severe cutaneous adverse reactions (SCARs) are the most common issue in the relief services for adverse health effects. After a report from Taiwan in 2004 that the HLA-B*15:02 allele was strongly associated with carbamazepine-induced Stevens-Johnson syndrome, many genetic association analyses have been reported for SCARs. To date, several HLA types have been reported to be associated with SCARs for about a dozen drugs, indicating involvement of immunological mechanisms. Three mechanistic concepts have been proposed for the initial pathogenesis of SCARs, including the presentation of drug molecules by direct non-covalent binding to HLA molecules (the p-i concept). In addition, granulysin released from cytotoxic T cells is involved in the skin damage. Furthermore, the mechanism of epidermal cell death has been shown to involve the induction of formyl peptide receptor 1 (FPR1) expression in the keratinocytes by an antimicrobial peptide LL-37 released from neutrophil, and then the FPR1-mediated necroptosis.</p><p> This presentation will overview the latest research results on SCARs and show prospective on their future evaluation in the non-clinical stage.</p>